Final answer:
To separate powder from salt water, if the powder is insoluble, use filtration. If the powder is soluble, distillation is appropriate. For large-scale operations, reverse osmosis could be employed.
Step-by-step explanation:
If a student is looking to separate powder from salt water, a suitable tool could be used depending on the characteristics of the powder and how it is mixed with the salt water. If the powder is insoluble, filtration using filter paper can efficiently separate the solid powder from the liquid. However, if the powder is soluble, distillation would be the appropriate method. In distillation, the water is evaporated and then condensed back into a separate container, leaving the salt behind. For large-scale operations such as desalination of water for a community, other techniques like reverse osmosis using a membrane could be utilized.
Reverse osmosis involves applying pressure to the saltwater against a membrane that allows only water molecules to pass through while blocking the salt. This process requires specialized equipment and is therefore commonly used in industrial or large-scale applications for water purification.
For a school project or laboratory setting, using distillation to separate salt from water would be a practical demonstration of this separation technique, and can be done with simple lab equipment such as a distillation apparatus.